Suspendable.java

package org.csstudio.dal;

/**
 * Interface for monitors that support suspend/resume operations.
 * 
 * @author Blaz Hostnik, Cosylab (blaz.hostnikATcosylab.com)
 */
public interface Suspendable {
	/**
	 * Suspends the monitor to stop receiving events flow
	 * from the data access event source.
	 * 
	 * @throws UnsupportedOperationException if suspend operation is not supported.
	 */
	public void suspend();
	
	/**
	 * Resumes the monitor to start again receiving events flow
	 * from the data access event source. <br>
	 * <b>Note:</b> if suspend was called several times, resume
	 * needs to be called same number of times to start receiving
	 * events again.
	 * 
	 * @throws UnsupportedOperationException if suspend operation is not supported.
	 */
	public void resume();
	
	/**
	 * Returns suspended state.
	 * @return Returns <code>true</code>, if monitor events flow is currently
	 * stopped, else <code>false</code>.
	 * 
	 * @throws UnsupportedOperationException if suspend operation is not supported.
	 */
	public boolean isSuspended();
}